dear Daisy, hi and thanks for your comment, which seems to be that you are caught up in a catch-22 situation.
At one moment she says that there will be a large inheritance, then next she wants some money back with interest and then says she has no money, well this would be rather confusing, especially when you are in desperate need of money, and only hoping it could be handed down, which is normally protocol.
You say that she is old, I'm 60 and are often referred to as being old, point taken, and as we become older our sanity does begin to dwindle, and I'm suggesting in any way that this happened with your mother, however as you have said that you' feel much better through your own hard work and determination', which is a great effort.
I would suggest for you to leave it alone and let 'bygones be bygones', and in the event that there is a large amount of money left in her will and not distributed fairly then you have the option of contesting her final decision.
A will can only be made by someone of 'sound mind', so if she was forced to sign a piece of paper not knowing what it is, then it's illegal. Geoff.